Stabilized nanocrystalline iron-based alloys: Guiding efforts in alloy selection

Using a modified regular solution model for grain boundary solute segregation, the relative thermal stability of a number of Fe-based nanocrystalline binary alloys was predicted with considerable accuracy. It was found that nanocrystalline iron was strongly stabilized by zirconium, moderately stabilized by tantalum, and not significantly stabilized by nickel or chromium. These findings are fully in line with the aforementioned predictions. This success with iron based alloys highlights the utility of this practical approach to selecting stabilizing solutes for nanocrystalline alloys.

► A regular solution model for solute segregation is capable of estimating the effect of solutes on the stability of nanocrystalline Fe.
► Stability increases for solutes having larger heats of segregation.
► Zr and Ta had an effect on stabilizing the nanocrystalline microstructure of Fe, while Cr and Ni did not.